1. Field of the Invention
The invention described herein relates to computer graphics, and more particularly to rendering and integration of a graphical user interface.
2. Background Art
In a typical computer graphics application, a user would generally like to be presented with two components. First, the user wants to be shown the computer graphics image that is the subject of the application's processing. This image is known hereinafter as the subject graphics image. Second, the user may want to be shown a graphical user interface (GUI). The GUI can include, for example, window borders, a cursor whose position corresponds to the position of appointing device (such as a mouse, light pen, or joystick), and a set of controls. The controls can include icons that, if chosen by the user, activate one or more processing routines. Commonly, both the subject graphics image and the GUI are rendered using a single graphics pipeline. Either the subject graphics or a GUI could be displayed at any time, but not both.
Moreover, in some systems, two rendering pipelines are used, one for the GUI and one for the subject graphics image. But such systems still do not show both the subject graphics image and the GUI to the user at the same time on a single display. Again, one or the other is shown at any given time. Clearly, for most graphics applications, the user would prefer to see both simultaneously.
Hence, there is a need for a computer graphics architecture in which a subject graphics image and a user interface are both are displayed to a user simultaneously.